Fuzz testing (fuzzing) is a powerful technique for generating large numbers of diverse inputs - either randomly or algorithmically - and dynamically invoking the code with those inputs. Even with random inputs, it is often capable of generating unexpected results such as crashes, memory corruption, or resource consumption. Fuzzing effectively produces repeatable test cases that clearly indicate bugs, which helps developers to diagnose the issues.
CWE-562 Base Draft
Return of Stack Variable Address
This vulnerability occurs when a function returns a pointer to its own local variable. Since that variable's memory is on the stack, the pointer becomes invalid as soon as the function finishes,…
Definition
What is CWE-562?
This vulnerability occurs when a function returns a pointer to its own local variable. Since that variable's memory is on the stack, the pointer becomes invalid as soon as the function finishes, leading to crashes or unpredictable behavior.
When a function declares a local variable, it's stored in a temporary memory region called the stack. This stack space is only reserved for the lifetime of that function call. Once the function returns, its stack frame is cleared and that memory is marked as available for the next function call. If you return a pointer to this now-freed location, you're handing the calling code a 'dangling pointer' to a memory address that is no longer guaranteed to hold your intended data.
The program may continue to run, but the next function that executes will likely reuse that same stack address for its own local variables, overwriting whatever value was there. Any subsequent attempt to read or write through the old pointer will access this new, unrelated data, causing corruption, logic errors, or most commonly, a sudden segmentation fault when the program tries to dereference the invalid pointer.
Real-world impact
Real-world CVEs caused by CWE-562
No public CVE references are linked to this CWE in MITRE's catalog yet.
How attackers exploit it
Step-by-step attacker path
- 1
Identify a code path that handles untrusted input without validation.
- 2
Craft a payload that exercises the unsafe behavior — injection, traversal, overflow, or logic abuse.
- 3
Deliver the payload through a normal request and observe the application's reaction.
- 4
Iterate until the response leaks data, executes attacker code, or escalates privileges.
Vulnerable code example
Vulnerable C
The following function returns a stack address.
char* getName() {
char name[STR_MAX];
fillInName(name);
return name;
} Secure code example
Secure pseudo
// Validate, sanitize, or use a safe API before reaching the sink.
function handleRequest(input) {
const safe = validateAndEscape(input);
return executeWithGuards(safe);
} What changed: the unsafe sink is replaced (or the input is validated/escaped) so the same payload no longer triggers the weakness.
Prevention checklist
How to prevent CWE-562
- Testing Use static analysis tools to spot return of the address of a stack variable.
Detection signals
How to detect CWE-562
Automated static analysis, commonly referred to as Static Application Security Testing (SAST), can find some instances of this weakness by analyzing source code (or binary/compiled code) without having to execute it. Typically, this is done by building a model of data flow and control flow, then searching for potentially-vulnerable patterns that connect "sources" (origins of input) with "sinks" (destinations where the data interacts with external components, a lower layer such as the OS, etc.)
Plexicus auto-detects CWE-562 and opens a fix PR in under 60 seconds.
Codex Remedium scans every commit, identifies this exact weakness, and ships a reviewer-ready pull request with the patch. No tickets. No hand-offs.
Frequently asked questions What is CWE-562?
How serious is CWE-562?
What languages or platforms are affected by CWE-562?
How can I prevent CWE-562?
How does Plexicus detect and fix CWE-562?
Where can I learn more about CWE-562?
Frequently asked questions
What is CWE-562?
This vulnerability occurs when a function returns a pointer to its own local variable. Since that variable's memory is on the stack, the pointer becomes invalid as soon as the function finishes, leading to crashes or unpredictable behavior.
How serious is CWE-562?
MITRE has not published a likelihood-of-exploit rating for this weakness. Treat it as medium-impact until your threat model proves otherwise.
What languages or platforms are affected by CWE-562?
MITRE lists the following affected platforms: C, C++.
How can I prevent CWE-562?
Use static analysis tools to spot return of the address of a stack variable.
How does Plexicus detect and fix CWE-562?
Plexicus's SAST engine matches the data-flow signature for CWE-562 on every commit. When a match is found, our Codex Remedium agent opens a fix PR with the corrected code, tests, and a one-line summary for the reviewer.
Where can I learn more about CWE-562?
MITRE publishes the canonical definition at https://cwe.mitre.org/data/definitions/562.html. You can also reference OWASP and NIST documentation for adjacent guidance.
Related weaknesses
Weaknesses related to CWE-562
CWE-758 Parent
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CWE-1038 Sibling
Insecure Automated Optimizations
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CWE-1102 Sibling
Reliance on Machine-Dependent Data Representation
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CWE-1103 Sibling
Use of Platform-Dependent Third Party Components
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CWE-1105 Sibling
Insufficient Encapsulation of Machine-Dependent Functionality
This weakness occurs when an application relies on hardware-specific or platform-dependent features but fails to isolate that code from…
CWE-474 Sibling
Use of Function with Inconsistent Implementations
This vulnerability occurs when code relies on a function whose behavior changes across different operating systems or versions, leading to…
CWE-587 Sibling
Assignment of a Fixed Address to a Pointer
This vulnerability occurs when code explicitly assigns a hardcoded memory address to a pointer, instead of using a dynamic or null value.
CWE-588 Sibling
Attempt to Access Child of a Non-structure Pointer
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CWE-672 Can precede
Operation on a Resource after Expiration or Release
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